1. Technical Field
The present disclosure relates to a variable displacement oil pump that can change the amount of oil discharged from its discharge port.
2. Description of Related Art
One example of variable displacement oil pumps is described in Japanese Patent Application Publication No. 2015-140670. This variable displacement oil pump has an adjustable member arranged in a housing space defined by a housing and a cover member, and can change the amount of oil discharged from its discharge port by shifting the adjustable member. A control oil chamber to which oil is supplied from an oil control valve is defined and formed by the adjustable member inside the housing space of the variable displacement oil pump. An urging member that applies an urging force to the adjustable member in a direction of reducing the volume of the control oil chamber is further provided inside the housing space.
The adjustable member of the above variable displacement oil pump is provided with long holes that regulate the shift direction of the adjustable member, and guide pins are inserted in these long holes. When the pressure inside the control oil chamber is changed through operation of the oil control valve, the adjustable member shifts in an extension direction of the long holes. As a result, the positional relation between the adjustable member and the discharge port changes, so that the amount of oil discharged from the discharge port changes.
In some cases, one end of the guide pin is a fixed end that is press-fitted into a first hole provided in the housing, while the other end of the guide pin is a free end that is loosely fitted into a second hole provided in the cover member. In such cases, the cover member is installed on the housing with the guide pin fixed to the housing. Thus, compared with when the other end of the guide pin is press-fitted into the second hole of the cover member, the other end of the guide pin is easy to insert into the second hole and the ease of installation can be enhanced accordingly.